1/*
2 * misc.c
3 *
4 * This is a collection of several routines from gzip-1.0.3
5 * adapted for Linux.
6 *
7 * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
8 * puts by Nick Holloway 1993, better puts by Martin Mares 1995
9 * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
10 */
11
12#define STANDALONE
13
14#include <linux/linkage.h>
15#include <linux/vmalloc.h>
16#include <linux/tty.h>
17#include <asm/io.h>
18
19/*
20 * gzip declarations
21 */
22
23#define OF(args)  args
24#define STATIC static
25
26#undef memset
27#undef memcpy
28
29/*
30 * Why do we do this? Don't ask me..
31 *
32 * Incomprehensible are the ways of bootloaders.
33 */
34static void* memset(void *, int, size_t);
35static void* memcpy(void *, __const void *, size_t);
36#define memzero(s, n)     memset ((s), 0, (n))
37
38typedef unsigned char  uch;
39typedef unsigned short ush;
40typedef unsigned long  ulg;
41
42#define WSIZE 0x8000		/* Window size must be at least 32k, */
43				/* and a power of two */
44
45static uch *inbuf;	     /* input buffer */
46static uch window[WSIZE];    /* Sliding window buffer */
47
48static unsigned insize = 0;  /* valid bytes in inbuf */
49static unsigned inptr = 0;   /* index of next byte to be processed in inbuf */
50static unsigned outcnt = 0;  /* bytes in output buffer */
51
52/* gzip flag byte */
53#define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */
54#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
55#define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
56#define ORIG_NAME    0x08 /* bit 3 set: original file name present */
57#define COMMENT      0x10 /* bit 4 set: file comment present */
58#define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
59#define RESERVED     0xC0 /* bit 6,7:   reserved */
60
61#define get_byte()  (inptr < insize ? inbuf[inptr++] : fill_inbuf())
62
63/* Diagnostic functions */
64#ifdef DEBUG
65#  define Assert(cond,msg) {if(!(cond)) error(msg);}
66#  define Trace(x) fprintf x
67#  define Tracev(x) {if (verbose) fprintf x ;}
68#  define Tracevv(x) {if (verbose>1) fprintf x ;}
69#  define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
70#  define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
71#else
72#  define Assert(cond,msg)
73#  define Trace(x)
74#  define Tracev(x)
75#  define Tracevv(x)
76#  define Tracec(c,x)
77#  define Tracecv(c,x)
78#endif
79
80static int  fill_inbuf(void);
81static void flush_window(void);
82static void error(char *m);
83static void gzip_mark(void **);
84static void gzip_release(void **);
85
86/*
87 * This is set up by the setup-routine at boot-time
88 */
89static unsigned char *real_mode; /* Pointer to real-mode data */
90
91#define EXT_MEM_K   (*(unsigned short *)(real_mode + 0x2))
92#ifndef STANDARD_MEMORY_BIOS_CALL
93#define ALT_MEM_K   (*(unsigned long *)(real_mode + 0x1e0))
94#endif
95#define SCREEN_INFO (*(struct screen_info *)(real_mode+0))
96
97extern char input_data[];
98extern int input_len;
99
100static long bytes_out = 0;
101static uch *output_data;
102static unsigned long output_ptr = 0;
103
104
105static void *malloc(int size);
106static void free(void *where);
107static void error(char *m);
108static void gzip_mark(void **);
109static void gzip_release(void **);
110
111static void puts(const char *);
112
113extern int end;
114static long free_mem_ptr = (long)&end;
115static long free_mem_end_ptr;
116
117#define INPLACE_MOVE_ROUTINE  0x1000
118#define LOW_BUFFER_START      0x2000
119#define LOW_BUFFER_MAX       0x90000
120#define HEAP_SIZE             0x3000
121static unsigned int low_buffer_end, low_buffer_size;
122static int high_loaded =0;
123static uch *high_buffer_start /* = (uch *)(((ulg)&end) + HEAP_SIZE)*/;
124
125static char *vidmem = (char *)0xb8000;
126static int vidport;
127static int lines, cols;
128
129#include "../../../../lib/inflate.c"
130
131static void *malloc(int size)
132{
133	void *p;
134
135	if (size <0) error("Malloc error\n");
136	if (free_mem_ptr <= 0) error("Memory error\n");
137
138	free_mem_ptr = (free_mem_ptr + 3) & ~3;	/* Align */
139
140	p = (void *)free_mem_ptr;
141	free_mem_ptr += size;
142
143	if (free_mem_ptr >= free_mem_end_ptr)
144		error("\nOut of memory\n");
145
146	return p;
147}
148
149static void free(void *where)
150{	/* Don't care */
151}
152
153static void gzip_mark(void **ptr)
154{
155	*ptr = (void *) free_mem_ptr;
156}
157
158static void gzip_release(void **ptr)
159{
160	free_mem_ptr = (long) *ptr;
161}
162
163static void scroll(void)
164{
165	int i;
166
167	memcpy ( vidmem, vidmem + cols * 2, ( lines - 1 ) * cols * 2 );
168	for ( i = ( lines - 1 ) * cols * 2; i < lines * cols * 2; i += 2 )
169		vidmem[i] = ' ';
170}
171
172static void puts(const char *s)
173{
174	int x,y,pos;
175	char c;
176
177	x = SCREEN_INFO.orig_x;
178	y = SCREEN_INFO.orig_y;
179
180	while ( ( c = *s++ ) != '\0' ) {
181		if ( c == '\n' ) {
182			x = 0;
183			if ( ++y >= lines ) {
184				scroll();
185				y--;
186			}
187		} else {
188			vidmem [ ( x + cols * y ) * 2 ] = c;
189			if ( ++x >= cols ) {
190				x = 0;
191				if ( ++y >= lines ) {
192					scroll();
193					y--;
194				}
195			}
196		}
197	}
198
199	SCREEN_INFO.orig_x = x;
200	SCREEN_INFO.orig_y = y;
201
202	pos = (x + cols * y) * 2;	/* Update cursor position */
203	outb_p(14, vidport);
204	outb_p(0xff & (pos >> 9), vidport+1);
205	outb_p(15, vidport);
206	outb_p(0xff & (pos >> 1), vidport+1);
207}
208
209static void* memset(void* s, int c, size_t n)
210{
211	int i;
212	char *ss = (char*)s;
213
214	for (i=0;i<n;i++) ss[i] = c;
215	return s;
216}
217
218static void* memcpy(void* __dest, __const void* __src,
219			    size_t __n)
220{
221	int i;
222	char *d = (char *)__dest, *s = (char *)__src;
223
224	for (i=0;i<__n;i++) d[i] = s[i];
225	return __dest;
226}
227
228/* ===========================================================================
229 * Fill the input buffer. This is called only when the buffer is empty
230 * and at least one byte is really needed.
231 */
232static int fill_inbuf(void)
233{
234	if (insize != 0) {
235		error("ran out of input data\n");
236	}
237
238	inbuf = input_data;
239	insize = input_len;
240	inptr = 1;
241	return inbuf[0];
242}
243
244/* ===========================================================================
245 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
246 * (Used for the decompressed data only.)
247 */
248static void flush_window_low(void)
249{
250    ulg c = crc;         /* temporary variable */
251    unsigned n;
252    uch *in, *out, ch;
253
254    in = window;
255    out = &output_data[output_ptr];
256    for (n = 0; n < outcnt; n++) {
257	    ch = *out++ = *in++;
258	    c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
259    }
260    crc = c;
261    bytes_out += (ulg)outcnt;
262    output_ptr += (ulg)outcnt;
263    outcnt = 0;
264}
265
266static void flush_window_high(void)
267{
268    ulg c = crc;         /* temporary variable */
269    unsigned n;
270    uch *in,  ch;
271    in = window;
272    for (n = 0; n < outcnt; n++) {
273	ch = *output_data++ = *in++;
274	if ((ulg)output_data == low_buffer_end) output_data=high_buffer_start;
275	c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
276    }
277    crc = c;
278    bytes_out += (ulg)outcnt;
279    outcnt = 0;
280}
281
282static void flush_window(void)
283{
284	if (high_loaded) flush_window_high();
285	else flush_window_low();
286}
287
288static void error(char *x)
289{
290	puts("\n\n");
291	puts(x);
292	puts("\n\n -- System halted");
293
294	while(1);	/* Halt */
295}
296
297#define STACK_SIZE (4096)
298
299long user_stack [STACK_SIZE];
300
301struct {
302	long * a;
303	short b;
304	} stack_start = { & user_stack [STACK_SIZE] , __KERNEL_DS };
305
306static void setup_normal_output_buffer(void)
307{
308#ifdef STANDARD_MEMORY_BIOS_CALL
309	if (EXT_MEM_K < 1024) error("Less than 2MB of memory.\n");
310#else
311	if ((ALT_MEM_K > EXT_MEM_K ? ALT_MEM_K : EXT_MEM_K) < 1024) error("Less than 2MB of memory.\n");
312#endif
313	output_data = (char *)0x100000; /* Points to 1M */
314	free_mem_end_ptr = (long)real_mode;
315}
316
317struct moveparams {
318	uch *low_buffer_start;  int lcount;
319	uch *high_buffer_start; int hcount;
320};
321
322static void setup_output_buffer_if_we_run_high(struct moveparams *mv)
323{
324	high_buffer_start = (uch *)(((ulg)&end) + HEAP_SIZE);
325#ifdef STANDARD_MEMORY_BIOS_CALL
326	if (EXT_MEM_K < (3*1024)) error("Less than 4MB of memory.\n");
327#else
328	if ((ALT_MEM_K > EXT_MEM_K ? ALT_MEM_K : EXT_MEM_K) < (3*1024)) error("Less than 4MB of memory.\n");
329#endif
330	mv->low_buffer_start = output_data = (char *)LOW_BUFFER_START;
331	low_buffer_end = ((unsigned int)real_mode > LOW_BUFFER_MAX
332	  ? LOW_BUFFER_MAX : (unsigned int)real_mode) & ~0xfff;
333	low_buffer_size = low_buffer_end - LOW_BUFFER_START;
334	high_loaded = 1;
335	free_mem_end_ptr = (long)high_buffer_start;
336	if ( (0x100000 + low_buffer_size) > ((ulg)high_buffer_start)) {
337		high_buffer_start = (uch *)(0x100000 + low_buffer_size);
338		mv->hcount = 0; /* say: we need not to move high_buffer */
339	}
340	else mv->hcount = -1;
341	mv->high_buffer_start = high_buffer_start;
342}
343
344static void close_output_buffer_if_we_run_high(struct moveparams *mv)
345{
346	if (bytes_out > low_buffer_size) {
347		mv->lcount = low_buffer_size;
348		if (mv->hcount)
349			mv->hcount = bytes_out - low_buffer_size;
350	} else {
351		mv->lcount = bytes_out;
352		mv->hcount = 0;
353	}
354}
355
356
357asmlinkage int decompress_kernel(struct moveparams *mv, void *rmode)
358{
359	real_mode = rmode;
360
361	if (SCREEN_INFO.orig_video_mode == 7) {
362		vidmem = (char *) 0xb0000;
363		vidport = 0x3b4;
364	} else {
365		vidmem = (char *) 0xb8000;
366		vidport = 0x3d4;
367	}
368
369	lines = SCREEN_INFO.orig_video_lines;
370	cols = SCREEN_INFO.orig_video_cols;
371
372	if (free_mem_ptr < 0x100000) setup_normal_output_buffer();
373	else setup_output_buffer_if_we_run_high(mv);
374
375	makecrc();
376	puts("Uncompressing Linux... ");
377	gunzip();
378	puts("Ok, booting the kernel.\n");
379	if (high_loaded) close_output_buffer_if_we_run_high(mv);
380	return high_loaded;
381}
382